APPLICANT'S ABSTRACT: The proposed application is designed to employ a novel procedure to study the learning variables involved in the development of behavioral tolerance to alcohol in humans. The initial experiment examines the development of acute tolerance within a day and behavioral tolerance (developed over consecutive days of exposure) using three different doses of ethanol and two different tasks. One task will be a computer controlled video game and the other task will be a pursuit-rotor task. The primary objective is to assess the sensitivity of the tasks to tolerance development and to investigate the dose response relationship across subjects. A behavioral study will examine the independence of performance on the tasks within subjects. If performance on the tasks are observed to be independent (i.e. performance on one task does not influence the performance level on the other task) both tasks may be used in other studies proposed. The remaining experiments will use the alcohol before - alcohol after task performance technique to control for the effects of alcohol exposure alone in contrast to task practice while intoxicated with alcohol. The role of performance feedback in tolerance development will be investigated in experiment 3 and transfer of tolerance and the effects of task difficulty will be examined in experiment 4. The results of the proposed studies could serve as behavioral baselines for future research into the role genetic risk factors and family history and their relation to behavioral tolerance. In addition, the procedure can serve to investigate the role of environmental cues, social learning variables and other variables of clinical relevance related to tolerance development in humans.